Remove DD extension when AV1 not preferred (#1129)

pkg/rtc/participant_sdp.go

@@ -8,6 +8,7 @@ import (
 	"github.com/pion/sdp/v3"
 	"github.com/pion/webrtc/v3"
 
+	dd "github.com/livekit/livekit-server/pkg/sfu/dependencydescriptor"
 	"github.com/livekit/protocol/livekit"
 	lksdp "github.com/livekit/protocol/sdp"
 )
@@ -113,27 +114,36 @@ func (p *ParticipantImpl) setCodecPreferencesVideoForPublisher(offer webrtc.Sess
 	}
 	p.pendingTracksLock.RUnlock()
 
-	if mime == "" {
-		return offer
-	}
-
-	codecs, err := codecsFromMediaDescription(lastVideo)
-	if err != nil {
-		return offer
-	}
-
 	mime = strings.ToUpper(mime)
-	var preferredCodecs, leftCodecs []string
-	for _, c := range codecs {
-		if strings.HasSuffix(mime, strings.ToUpper(c.Name)) {
-			preferredCodecs = append(preferredCodecs, strconv.FormatInt(int64(c.PayloadType), 10))
-		} else {
-			leftCodecs = append(leftCodecs, strconv.FormatInt(int64(c.PayloadType), 10))
+	// remove dd extension if av1 not preferred
+	if !strings.Contains(mime, "AV1") {
+		for i, attr := range lastVideo.Attributes {
+			if strings.Contains(attr.Value, dd.ExtensionUrl) {
+				lastVideo.Attributes[i] = lastVideo.Attributes[len(lastVideo.Attributes)-1]
+				lastVideo.Attributes = lastVideo.Attributes[:len(lastVideo.Attributes)-1]
+				break
+			}
 		}
 	}
 
-	lastVideo.MediaName.Formats = append(lastVideo.MediaName.Formats[:0], preferredCodecs...)
-	lastVideo.MediaName.Formats = append(lastVideo.MediaName.Formats, leftCodecs...)
+	if mime != "" {
+		codecs, err := codecsFromMediaDescription(lastVideo)
+		if err != nil {
+			return offer
+		}
+
+		var preferredCodecs, leftCodecs []string
+		for _, c := range codecs {
+			if strings.HasSuffix(mime, strings.ToUpper(c.Name)) {
+				preferredCodecs = append(preferredCodecs, strconv.FormatInt(int64(c.PayloadType), 10))
+			} else {
+				leftCodecs = append(leftCodecs, strconv.FormatInt(int64(c.PayloadType), 10))
+			}
+		}
+
+		lastVideo.MediaName.Formats = append(lastVideo.MediaName.Formats[:0], preferredCodecs...)
+		lastVideo.MediaName.Formats = append(lastVideo.MediaName.Formats, leftCodecs...)
+	}
 
 	bytes, err := parsed.Marshal()
 	if err != nil {

pkg/sfu/buffer/buffer.go

@@ -510,7 +510,6 @@ func (b *Buffer) getExtPacket(rawPacket []byte, rtpPacket *rtp.Packet, arrivalTi
 			b.logger.Warnw("could not unmarshal VP8 packet", err)
 			return nil
 		}
-		ep.Payload = vp8Packet
 		ep.KeyFrame = vp8Packet.IsKeyFrame
 		if ep.DependencyDescriptor == nil {
 			ep.Temporal = int32(vp8Packet.TID)
@@ -519,6 +518,7 @@ func (b *Buffer) getExtPacket(rawPacket []byte, rtpPacket *rtp.Packet, arrivalTi
 			vp8Packet.TID = uint8(ep.Temporal)
 			ep.Spatial = InvalidLayerSpatial // vp8 don't have spatial scalability, reset to -1
 		}
+		ep.Payload = vp8Packet
 	case "video/h264":
 		ep.KeyFrame = IsH264Keyframe(rtpPacket.Payload)
 	case "video/av1":